Evaluation of fish-injury mechanisms during exposure to turbulent shear flow

• Published in: Canadian journal of fisheries and aquatic sciences 2005-07, Vol.62 (7), p.1513-1522
• Main Authors: Deng, Zhiqun, Guensch, Gregory R, McKinstry, Craig A, Mueller, Robert P, Dauble, Dennis D, Richmond, Marshall C
• Format: Article
• Language: English
• Subjects: Animal, plant and microbial ecology; Applied ecology; Biodiversity; Biological and medical sciences; Conservation, protection and management of environment and wildlife; Environmental degradation: ecosystems survey and restoration; Exposure; Fish; Fish hatcheries; Fundamental and applied biological sciences. Psychology; Injuries; Marine; Mortality; Oncorhynchus tshawytscha; Salmon; Shear stress; Time series; Turbines; Turbulent flow; Velocity
• ISSN: 0706-652X; 1205-7533
• DOI: 10.1139/f05-091

Understanding the factors that injure or kill turbine-passed fish is important to the operation and design of the turbines. Motion-tracking analysis was performed on high-speed, high-resolution digital videos of juvenile salmonids exposed to a laboratory-generated shear environment to isolate injury mechanisms. Hatchery-reared fall chinook salmon (Oncorhynchus tshawytscha, 93–128 mm in length) were introduced into a submerged, 6.35-cm-diameter water jet at velocities ranging from 12.2 to 19.8 m·s –1 , with a reference control group released at 3 m·s –1 . Injuries typical of turbine-passed fish were observed and recorded. Three-dimensional trajectories were generated for four locations on each fish released. Time series of velocity, acceleration, force, jerk, and bending angle were computed from the three-dimensional trajectories. The onset of minor, major, and fatal injuries occurred at nozzle velocities of 12.2, 13.7, and 16.8 m·s –1 , respectively. Opercle injuries occurred at 12.2 m·s –1 nozzle velocity, while eye injuries, bruising, and loss of equilibrium were common at velocities of 16.8 m·s –1 and above. Of the computed dynamic parameters, acceleration showed the strongest predictive power for eye and opercle injuries and overall injury level, and it may provide the best potential link between laboratory studies of fish injury, field studies designed to collect similar data in situ, and numerical modeling.